Vacuum-dredger.



L. B. GRAY.

VACUUM DRBDGER.

APPLICATION FILED AUG. 29, 1910. RENEWED AUG. 25, 1911.

Patented Nov. 11, 1913.

TE STATES a1 mos.

LAWRENCE B. GRAY, 01"; BUS-TOM, MASSAGHUSETTS, ASSIGNOB 'IO HYDRAULIC VACUUM DREDGING COMPANY, OF WILMINGTON, DELAWARE, A GORPORATION OF DELAe wean.

vAouUM-nasnoEn.

Specification of Letters Patent.

Patented Nov. 11, 19,13.

Application filed August 29, 1910, Serial No. 579/1131." Renewed August 25, 1911. Serial No. 646,035

To all whom it may concern.-

Be it known that I, LAWRENCE B. GRAY, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Vacuum- Dredgers, of which the following is a specification.

This invention relates to apparatus by which material may be raised, particularly from the bottom of a stream or other body of water, by means of atmospheric pressure, and more particularly to those dredges in which the vacuum is produced by the sudden condensation of a body of steam at a high temperature contained in a closed chamber.

The objects of the invention are mainly to produce certain improvements in steam dredges by which greater strength, greater stability, and greater ease of ope *ation are obtained than. in such dredges as have heretofore been devised, and also to provide which is also the receiving chamber. Fig. 0

is a fragmentary elevation of the lower end of this chamber and the gate.

The same reference characters indicate the same parts in all the figures.

When used for dredging the bottom of a body of water, the apparatus may conveniently be mounted upon a floating support such as a scow or float a, although if desired it may be mounted upon a platform on the shore In the drawings, however, it is shown as floating on a boat. The apparatus consists of a vacuum chamber and receiver Z), to which is connected an induction tube a, and a single pipe (l through which steam and water are admitted. The receiver b is made preferably of steel plates strongly riveted together, and is of peculiar shape by virtue of which it is enabled to resist most effectively the enormous pressure of the external atmosphere when a vacuum is produced in its interior, and is at the same time capable of tilting easily when the induction end of the inctrically opposite sides thereof are trunnions e which pass through bearings f in a carriage g on'which the receiver is sup ported, such carriage being conveniently an annular or semi-circular member supported itself at three or more points in a manner permitting it to swing about a vertical axis.

By virtue of the trunnions 6 having a piv otal bearing in the carriage, the receiver can tilt easily when the induction pipe is raised above the bottom, and when it is lowered into the bottom.

The carriage itself rests upon a toothed annular or gear shaped support it and carries three or more pinions 2' meshing with the teeth of such support, by which it is so held that it may easily revolve so as to permit the induction pipe to swing from side to side.

Two of the pinions 2' are mounted upon the same trunnions c by which the receiver is supported on the carriage, while the other pimon is mounted on a stud jprojccting from the carriage g at an intermediate point.

All of these trunnions are provided with roller bearings, one of which is indicated at is in Fig. 3. The carriage is prevented from being lifted or displaced from the supporting annular gear h by means of rolls Z which are j ournalcd upon pins as projecting downwardly from the carriage at a number of points, and underlying a part of the support it. The contacting surfaces of the support and rolls are beveled to eliminate friction, and are represented by 7b and Z respectively.

Connected to the steam and water inlet of the receiver Z) is a Y-branch it having its branches connected with pipes o and p respectively, one of which is connected to a steam boiler or superheater, and the other to a tank or pump from which cold water is supplied. For the purpose of convenience in the following description, it may be assumed that the pipe 0 is the steam pipe, and p the water pipe. In the branch at is a 2-way cock 7, which may be so placed as to admiteither steam or water exclusively. This cock is operated by a handle g, by virtue of which a rapid and wide movement of the cock is obtained with a relatively slight movement of the handle. This valve is a new invention of mine, which forms the subject of a separate application filed concurrently herewith.

In the induction pipe is contained a valve T which opens, inwardly when a vacuum is produced in the chamber 5 to admit the material lifted thereby, to which is connected an external handle or lever r, and a second inwardly opening valve 1*. The latter operates as a vacuum safety valve to prevent collapse of the receiver by unbalanced external pressure in case the induction pipe should be so obstructed that the matter cannot flow into the receiver to fill the vacuum. Both valves are arranged in a fitting or valve chamber which is interposed between the induction pipe and the inlet to the vacuum chamber. Thesea-t for the valve 9 is in a plane crossing the aassage in the induction pipe, while the seat for the valve 7 surrounds an opening which communicates with the outer atmosphere. The valve 1 is an important accessory to the apparatus, since it is so arranged as to close under the action of excess pressure inside the vacuum chamber, thus preventing escape of the steam which is blown into the chamber preparatory to producing the vacuum, and it also serves to prevent back flow of the dredged material from the vacuum chamber.

One of the improvements constituting a feature of the present invention is the fitting through which the steam and water are admitted to the receiver, and the means by which this fitting is secured to the receiver. The pipe cl as shown in Fig. 3 is formed upon or secured to a disk d, which is spherically curved to fit the inside of the receiver, and the pipe passes through an opening in the shell of the latter. A clamp (Z which fits the exterior of the receiver is threaded upon the pipe and is screwed tightly against the latter, whereby the latter is securely and tightly clamped in a manner such as to prevent any serious amount of leakage into or out of the receiver. The disk d has an internally threaded rim in which is screwed a disk .9. The disks are so formed that a space is left between them suflicient to allow water or steam to be distributed over the inner disk 8 and the latter is perforated for the purpose particularly of distributing the water in a spray or in fine streams over the entire interior of the chamber. The detachably threaded connection between the disks is provided to permit. their separation for cleaning purposes.

The lower part of the chamber, as previously stated, is conical in form, being truncated so as to leave a large discharge opening in its bottom, from which the matter drawn into the chamber by the vacuum is discharged. This opening is closed when the apparatus is in operation by agate 2? which is hinged at z" to the receiver. It swings downwardly when open, and has a handle t by which it is operated.

The reference character t designates the side bars of a U-shaped frame which carries the handle 2?, said side bars being fastened to the gate. The hinge between the handle and the body of the vacuum chamber is formed by a pintle contained in a projection at the side of the chamber mouth and entering at its ends suitable sockets provided in the mem ers 26 A lock for the gate is provided in the form of a double-armed latch u pivoted centrally on the gate at u, and arranged to be caught by hooks o and Q). These hooks are arranged at diametrically opposite sides of the discharge opening, the latter hook being for convenience formed upon the hinge t. The handle of the latch when closed lies close beside the gate handle t and is easily accessible. When open it occupies the dotted-line position shown in Fig. l. By reason of the hooks on opposite sides of the opening, the gate when closed tight may be made steam-tight and air-tight, particularly if the hooks are somewhat wedge-shaped, as they may very easily be made. Thus the hinge may be made free enough to enable the gate to be easily closed without impairing the tightness with which the gate may be closed. On the receiver is a pressure gage to.

In operating the dredger the vacuum chamber is filled with steam, by which all air is expelled. This steam at from $0 to 50 pounds pressure, and preferably superheated, is then suddenly chilled and condensed by jets of cold water forced through the perforated disk .9. The sudden chilling of the steam lowers its pressure far below the atmospheric pressure, whereby the water and solid matter adjacent to the inlet end of the induction pipe are drawn into the vacuum chamber or receiver. In this alternate admission of water and steam, the feature of admitting both fluids to a single pipe and of having one valve with means for quickly operating it to shut off one fluid and admit the other almost instantaneously, is of very great importance. So also are the shape of the vacuum chamber and the vacuum valve 1", by virtue of which danger of collapse of the vacuum chamber is avoided and thus such thick and heavy material need not be employed in the construction of its shell as would be necessary if these features were not present. As the vacuum chamber is ordinarily made very large, say twelve feet or more in height, and correspondingly wide, it is subjected to an enormous external pressure when there is a vacuum in its interior. The spherical form of the top of the chamber affords the greatest ,possible resistance to collapse, while the conical form of the lower part affords the greatest possible strength, while at the same time enabling the receiver to be so supported that it can tilt without materially shifting the position of its outlet, and also to give the form of outlet enabling easy and quick discharge of all its solid contents to be effected.

When the gate t is opened after a filling of the receiver, the contents of the latter fall. upon a grate a: and the liquid and finer solid portions of such contents pass through the grate into a sluice-way 3 while bowlders and fragments too large to pass through the grate are carried off at the side thereof over a grid 3 and out through a chute 11 at the side of the sluice. A stop bar y is placed diagonally across the top of the sluice at the opening of the chute, and serves to cause the large pieces to fall overboard without being handled. As shown in Fig. 1, the bars of which the grid 3 is composed are curved upward at their farther ends and attached to the stop bar y.

Below the gear-shaped support It is a curved wall or barbette 2 inclosing the grate m and the space into which the receiving chamber discharges. Doors 2 are left in the wall a to enable attendants to enter and clear the grate of pieces lodging in its interstices.

I claim,

1. In a vacuum apparatus of the character described, the combination of a vacuum chamber having an outlet'at its bottom, an induction pipe connected to said vacuum chamber, and means supporting the vacuum chamber so that it may rotate about its own axis and tilt in directions perpendicular to its axis, consisting of trunnions projecting laterally from the receiver near its lower end, toothed rolls journaled on said trunnions, whereby tilting of the receiver is permitted without materially shifting the loca tion of its outlet, and a circular toothed support on which said rolls rest, the teeth of the rolls and support being in mesh and retaining the chamber in proper engagement with the support, while permitting revolu tion about its axis.

2. A vacuum dredging apparatus comprising a chamber having an outlet at its bottom, a pipe leading outwardly and downwardly from said chamber, pipes for conducting steam and water to said chamber,

a fixed horizontal support for the chambersurrounding the bottom thereof and having the form of a bevel gear with teeth on its upper side, trunnions projecting from opposite sides of the chamber, rolls in the form of bevel pinions rotatably mounted on said trunnions and resting on and meshing with the teeth of said support, whereby the cham her is supported in a manner permitting rotation about an upright axis and tilting about the axis of the trunnions, a connecting member or yoke journaled on the trunnions and an intermediate roll pivoted to said connecting member and resting on the support.

In a vacuum dredger, a receiver having an outlet at its bottom, a gate hingedly connected to the receiver at one side 01 such out let and movable to close and open the same, a handle secured to the gate and extending beyond the hinge, and a latch pivotally mounted upon the gate and operable to engage portions of the receiver on opposite sides of the gate when the latter is closed to hold and crowd the latter shut, independently of the hinge, and having a hand grip parallel and close to the said handle, when closed.

4. In a vacuum apparatus of the character described, a vacuum chamber having a spherically curved portion, an inlet fitting consisting of a disk shaped to fit against the inside of the wall of the chamber and having a tubular part passing through said wall, and a perforated disk having a screw threaded engagement at its periphery with the first-named disk, whereby it may be re-- moved for cleaning the interior of the sprinkler.

5. In a vacuum dredging apparatus of the character described, a vacuum chamber having a spherically curved wall, a conduit for admitting fluid to the chamber passing through the wall thereof, having a spherically convex enlargement on its inner end. fitting the inside of the wall, and having a threaded flange on its peripher means for securing the conduit in place, consisting of a cap or nut threaded upon the conduit outside of the chamber wall and shaped with a spherical concavity to fit against the wall,

and a sprinkler disk threaded at its periphery and detachably screwed into said flange.

6. In a vacuum dredge a vacuum chamber, a yoke-shaped carriage having arms embracing the lower part of the chamber, trunnions passing from the chamber through the arms of the carriage and having bearings therein whereby the chamber is enabled to tilt, wheels mounted on the said trunnions whereby the carriage and chamber are both supported and enabled to revolve, and a supporting wheel connected to the carriage at an intermediate point.

In testimony whereof I have aflixedmy signature, in presence or two witnesses.

LAWRENCE B. GRAY. V

W'itncsses A. H. BnoWN, P. W. Prizzn'rri.

Copies of this patent may be obtained for five cents each. by addressing the Commissioner of Patents, Washington, D. G." 

